Method and Apparatus for Uplink Transmission and Reception in a Wireless Communication System

1. A method of performing an uplink transmission in a wireless communication system by a user equipment (UE), the method comprising: receiving, from a base station, downlink control information (DCI) for a scheduling of an uplink shared channel; and performing the uplink transmission via the uplink shared channel based on the DCI, wherein the DCI includes a sounding reference signal resource indication (SRS resource indication, SRI) field carrying a SRI and a demodulation reference signal (DMRS) related field, wherein a number of layers for the uplink transmission is determined based on the SRI field, wherein a number of DMRS states for the uplink transmission is differently configured according to the number of layers, and wherein a size of the DMRS related field is configured with a minimum bitwidth representing for a maximum number of DMRS states for the uplink transmission.

2. The method of claim 1 , wherein the DMRS related field is a field configured for a port configuration of the DMRS.

3. The method of claim 1 , wherein the size of the DMRS related field is same for candidates of the number of layers applicable to the uplink transmission.

4. The method of claim 3 , wherein the uplink transmission is performed based on a non-codebook.

5. The method of claim 3 , wherein a bitwidth of the SRI field is determined based on a number of SRS resources in a SRS resource set configured to the UE and a maximum number of layers supported for the uplink transmission.

7. A method of performing an uplink reception in a wireless communication system by a base station, the method comprising: transmitting, to a user equipment (UE), downlink control information (DCI) for a scheduling of an uplink shared channel; and performing the uplink reception via the uplink shared channel based on the DCI, wherein the DCI includes a sounding reference signal resource indication (SRS resource indication, SRI) field carrying a SRI and a demodulation reference signal (DMRS) related field, wherein a number of layers for uplink transmission is determined based on the SRI field, wherein a number of DMRS states of the DMRS related field is differently configured according to the number of layers, and wherein a size of the DMRS related field is configured with a minimum bitwidth representing for a maximum number of DMRS states for the uplink transmission.

8. The method of claim 7 , wherein the DMRS related field is a field configured for a port configuration of the DMRS.

9. The method of claim 7 , wherein the size of the DMRS related field is same for candidates of the number of layers applicable to the uplink transmission.

10. The method of claim 9 , wherein the uplink reception is performed based on a non-codebook.

11. The method of claim 9 , wherein a bitwidth of the SRI field is determined based on a number of SRS resources in a SRS resource set configured to the UE and a maximum number of layers supported for the uplink reception.

13. A user equipment (UE) configured to perform an uplink transmission in a wireless communication system, the UE comprising: a transceiver configured to transmit and receive a radio signal; and a processor configured to control the transceiver, wherein the processor is configured to: receive, from a base station, downlink control information (DCI) for a scheduling of an uplink shared channel; and perform the uplink transmission via the uplink shared channel based on the DCI, wherein the DCI includes a sounding reference signal resource indication (SRS resource indication, SRI) field carrying a SRI and a demodulation reference signal (DMRS) related field, wherein a number of layers for the uplink transmission is determined based on the SRI field, wherein a number of DMRS states of the DMRS related field is differently configured according to the number of layers, and wherein a size of the DMRS related field is configured with a minimum bitwidth representing for a maximum number of DMRS states for the uplink transmission.